1. Field of the Invention
The present invention relates to an X-ray fluorescence analyzer that is capable of detecting toxic substances or the like and that is used for screening products or measuring a film thickness of plating or the like and an X-ray fluorescence analyzing method using the X-ray fluorescence analyzer.
2. Description of the Related Art
In a fluorescent X-ray analysis, a spectrum is acquired from energy by irradiating a sample with X-rays emitted from an X-ray source and detecting fluorescent X-rays which are characteristic X-rays emitted from the sample using an X-ray detector, and a qualitative analysis or a quantitative analysis of the sample or film thickness measurement of the sample is performed. Since samples can be rapidly analyzed in a non-destructive manner by the fluorescent X-ray analysis, the fluorescent X-ray analysis is widely used in the fields of process control, quality control, and the like. In recent years, high precision and high sensitivity of the fluorescent X-ray analysis have been achieved, and thus microdetermination is enabled. In particular, the fluorescent X-ray analysis is expected to become widespread as an analysis method of detecting toxic substances contained in materials, complex electronic parts, or the like.
For example, as illustrated in FIG. 5, an X-ray fluorescence analyzer according to the related art is provided with an X stage (not illustrated) that moves a sample stage 2 on which a sample S is mounted in the X direction, a Y stage (not illustrated) that moves the sample stage 2 in the Y direction, and an X-ray shielding enclosure 108 that accommodates the X stage and the Y stage therein so as to prevent or suppress exposure of an operator in measuring a sample. In this apparatus, it is necessary to ensure the size of the X-ray shielding enclosure 108 to be large enough to receive movable ranges of the X stage and the Y stage.
For example, JP-A-2002-005858 discloses a total-reflecting X-ray fluorescence analyzer provided with an X stage that moves a sample stage on which a disc-like sample is mounted in the X direction, a Y stage that moves the sample stage in the Y direction, and a θ stage that rotates the sample stage around a rotation axis perpendicular to the X stage and the Y stage. In this apparatus, for example, when a desired measurement part is present on the left side of the center of the sample and an irradiation position with primary X-rays is present on the right side, the desired measurement part is arranged at a position which is irradiated with primary X-rays by appropriately rotating the sample (for example, by 180 degrees) on a horizontal plane using the θ stage to position the desired measurement part on the right side of the center of the sample.
In the related art, the following problems may remain.
In the X-ray fluorescence analyzer according to the related art, particularly, when a large-area sample such as an electronic printed circuit board is measured, it is necessary to increase the movable ranges of the X stage and the Y stage so as to measure the entire surface of the sample. For example, as illustrated in FIG. 5, a wide movable range H1 corresponding to the area of the sample S is necessary, a sample stage movable range which is four times the sample area is necessary, the X-ray shielding enclosure 108 increases in size, an occupied area for installation of the apparatus increases, and thus there is a problem in that it is difficult to secure an installation location of the apparatus. Even when an installation location is secured, a sample input/output door of the apparatus increases in size and an opening and closing operation thereof imposes a burden on an operator. In order to solve this problem, means for reducing the occupied area of the apparatus by setting a measured head party in which an X-ray generating system or a detection system is disposed to be movable, but a moving mechanism of the measurement head increases in size and thus there is a problem in that apparatus costs increase and the measurement position is not stabilized.
In the conventional apparatus described in JP-A-2002-005858, since the θ stage is provided, a part which cannot be irradiated with primary X-rays only by the movements of the X stage and the Y stage is moved to an irradiation position with primary X-rays by rotating a disc-like sample. However, in this apparatus, a disc-like sample is merely rotated by 180 degrees to face the opposite side for the purpose of measuring the disc-like sample. Accordingly, when a large-area sample such as an electronic printed circuit board is measured, there is a problem in that the measurement cannot be efficiently performed. Particularly, when the X stage and the Y stage having a small movable range are employed to decrease the size of the apparatus, the entire surface of a sample cannot be efficiently measured only by properly rotating the θ stage.
Since the conventional apparatus described in JP-A-2002-005858 is a total reflecting type in which a sample is obliquely irradiated with primary X-rays, the X-ray source needs to be installed to depart from the position immediately above the sample and thus there is a problem in that the X-ray shielding enclosure should be increased in size in the horizontal direction for the purpose of accommodating the X-ray source.